French Patent Application No. 93 01410 already describes a closure device for a recipient with threaded neck, comprising a tapped closure of which the lower part is attached to a guarantee strip by a zone of connection with low mechanical resistance; said strip presenting an elastically deformable, inner, annular bead intended to clip beneath a holding flange made on the lower periphery of said neck by forced screwing of the closure and an outer peripheral boss separated from said bead by a zone with controlled elastic deformation.
However, when the strip is immobilized since the bead is in bearing abutment on the flange of the recipient and screwing continues, there are produced a compression and a relative displacement of the closure with respect to the strip which provokes rupture of the zone of connection of low mechanical resistance before the bead has passed beneath the flange.
Now, in order to perfect the guarantee strip, it is desirable to make a considerably projecting inner bead whilst fragilizing to a maximum the zone of connection in order to guarantee the obviousness of the first opening, whilst facilitating it.
It is an object of the present invention satisfactorily to overcome the technical problems set forth hereinabove.